In recent times, nano-sized metal chalcogenides materials have been the subject of significant research due to their potential applications as biological markers, nonlinear optical materials, luminescent devices, photodetectors, catalysts, and chemical sensors, etc. One known method to prepare metal chalcogenide nanomaterials involves reaction in a confined medium such as microemulsion or polymer matrix whereby difficulty has been encountered in producing particles of uniform sizes.
One known method involves thermolysis of an organometallic precursor in the presence of a chalcogen source at relatively high temperatures in the range of 120° C. to 300° C. The high temperatures utilised in these known methods are disadvantageous in that the reactants may be rendered hazardous to handle, may require the use of specialised equipment and utilise significant amounts of energy in the reaction. Furthermore, the reaction may require the use of an inert atmosphere. In addition, some of the precursors may have to be prepared under special conditions, as they are hazardous and may be explosive in nature. This increases the cost of producing metal chalcogenide particles, particularly on an industrial scale.
While many studies have focused on the control of nanoparticles sizes for their quantum confined properties, the ability to produce monodispersed nanocrystals with predictable shape remains an intricate challenge in nanomaterials synthesis. The simultaneous control of crystal shapes, in addition to their sizes and the higher surface-to-volume ratio, would be advantageous.
Controlling the shape of nanoparticles has thus far been achieved in two ways:                (i) using a template (e.g. porous alumina, polymer membranes, carbon nanotubes and rodlike micelles); and        (ii) in solutions by employing appropriate capping agents (e.g. surfactants, polymers, and ligands).        
The latter method is more attractive due to higher yield and simplicity, without the need of removing the template after preparation. Among the solution methods, the injection of an organometallic precursor into a hot coordinating solvent provides a simple route to produce particles with desirable properties (i.e. high crystallinity, uniform shapes and sizes with a high degree of monodispersity). However, such method usually involves elaborate preparation of air-sensitive organometallic complexes that decompose exothermically in air, and also the use of high temperatures as outlines above.
There is a need to provide a method of preparing metal chalcogenide particles, and in particular nano-sized chalcogenide particles, that overcome or at least ameliorate one or more of the disadvantages described above.
There is a need to provide a method of preparing nano-sized metal chalcogenide particles in which the shape and size of the formed particles can be controlled.